This invention relates to valves.
Straight-through flow is a well-known characteristic of gate valves, which have only two conditions: wide-open and closed. In globe valves, in which flow is variable between those two conditions, in the wide-open condition there is neither straight-through flow nor a seat which does not obtrude into the flow passage to act as a source of friction and turbulence. In McMullen U.S. Pat. No. 2,445,885, flow is generally straight-through, but an angled seat obtrudes into and thereby narrows the flow passage. In Baker et al. U.S. Pat. No. 668,946, the seat and passage diameters are about the same, but the seat and seat support so obtrude into the flow passage that flow must be diverted upward and then downward from its normal straight-line axis. Green U.S. Pat. No. 2,801,820 shows straight-through flow in a valve capable of metering, but the stem is perpendicular to the flow passage, as in a gate valve.